User:Mary Ball/Leptin

HUMAN OBESITY PROTEIN, LEPTIN
Mutations in the obese gene (OB) or in the gene encoding the OB receptor(OB-R) result in obesity, infertility and diabetes in a variety of mouse phenotypes. The demonstration that OB protein (also known as leptin) can normalize body weight in ob/ob mice has generated enormous interest. Most human obesity does not appear to result from a mutant form of leptin: rather, serum leptin concentrations are increased and there is an apparent inability to transport it to the central nervous system (CNS). Injection of leptin into the CNS of overfed rodents resistant to peripheral administration was found to induce biological activity. Consequently, for the leptin to act as a weight-lowering hormone in human obesity, it appears that appropriate concentrations must be present in the CNS. This places a premium on understanding the structure of the hormone in order to design more potent and selective agonists.

Quiz
{Most human obesity is the result of mutant forms of leptin. - True + False
 * type=""}
 * Most obese humans actually have increased concentrations of normal leptin. So maybe cells in the brains of many obese people are just unresponsive to leptin.

{Leptin is a type of: - Gene + Protein - RNA - Carbohydrate
 * type=""}
 * The mouse gene named obese was found to code for a protein, which was named leptin.

{ What gene symbol was assigned to the obese gene? { OB }
 * type="{}"}

{What is the biological function of leptin? - It is an enzyme. - It is a membrane receptor. + It is a hormone. - It is an intracellular hormone receptor.
 * type=""}

{ Which of these structures represents Leptin? - + - -
 * type=""}

Additional Reading

 * "Gimmick-Free Weight-Loss Pill in the Works", January 2010 article from Science Daily News.


 * Article on the Discovery of Leptin from the Howard Hughes Medical Institute.

About this Structure
1AX8 is a 1 chain structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.

Reference
Page seeded by OCA on Tue Feb 17 06:36:47 2009